I have steered away from using cloud services because I do suspect that the firms that offer cloud services for taxes are major targets for hackers. All companies that have been hacked in the past (Turbotax, Wells Fargo. Blue Shield, Yahoo, Experian, the IRS, to name a few), didn't notify their own customers in a timely matter. The liability of going to the cloud rests with the accounting firm. Not the provider of these cloud services like TR, for example. So please make sure you have adequate liability insurance for when, not if, your cloud service gets hacked and your clients information hits the black market and your clients ask you for an explanation. You may want to let your client know, in advance, that you share their financial information with cloud based services which may be more prone to hackers.